Seven-year follow-up of LASIK for myopia

Long-term efficacy and safety profiles following small incision lenticule extraction in eyes with ≥ 5-year follow-up

PURPOSE

To evaluate long-term efficacy, safety, predictability and stability (refractive and keratometric) of myopic and myopic astigmatism correction with Small Incision Lenticule Extraction (SMILE).

METHODS

Single center retrospective review of eyes undergoing SMILE from 2012-2015. Forty-two eyes (23 patients) with ≥ 5-year follow-up. Variables analyzed were preoperative, 3-month, 1-year and last follow-up uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE) and mean keratometry. Descriptive statistics were performed and results reported following the Standard for Reporting Astigmatism Outcomes.

RESULTS

Mean follow-up of 5.98 ± 0.90 years. Mean preoperative SE was -5.26 ± 1.22D (range -2.50 to -8.12D). Mean preoperative cylinder was -0.66 ± 0.61D (range 0.00 to -2.25D). Efficacy and safety indices were 0.86 and 0.98, respectively. In total, 81% of operated eyes achieved an UDVA of ≥ 0.09 logMar (20/25 Snellen). At the last follow-up, ≥1 line of CDVA was gained in 14% of eyes. Five percent lost 1 line of CDVA, and no eye loss ≥2 lines of CDVA. Sixty-nine percent of eyes were within ± 0.50D and 86% within ± 1.00D of the attempted SE correction. Ninety-one percent of eyes had ≤0.50D of postoperative astigmatism and 71% were within ± 15° from the intended correction axis. At the final follow-up, a statistically significant myopic regression of 0.19 ± 0.50D was observed (p = 0.01).

CONCLUSIONS

Long-term results demonstrate that SMILE is effective, predictable and safe. SMILE has good stability, low regression compared to LASIK, and no signs of corneal ectasia staging within our standard criteria.

Ocular Pain Symptoms in Individuals With and Without a History of Refractive Surgery: Results From a Cross-Sectional Survey

PURPOSE

This study characterized ocular pain symptoms in individuals with and without a history of refractive surgery (RS) using a cross-sectional survey of individuals with ocular pain.

METHODS

A link to an anonymous survey was posted on a corneal neuralgia Facebook group that included individuals with ocular pain from any etiology and sent to individuals seen in our clinic with ocular pain. The survey asked about medical history, ocular pain symptoms (using standardized questionnaires), and treatment responses. Respondents were split into 2 groups based on a history of RS.

RESULTS

One hundred one individuals responded to the survey. The mean age for all respondents was 41.6 ± 15.6 years, and 50% reported a history of RS. A total of 46% of individuals with a history of RS reported that their ocular pain started within 1 month of surgery, with median pain duration of 36 (interquartile range 22-84) months. The median Dry Eye Questionnaire-5 (range 0-22) scores were 16 and 15 for the RS and no-RS groups, respectively. Most individuals in both groups characterized their pain as burning (score ≥1: RS, 86%; no-RS, 80%) and reported evoked pain to wind, light, or temperature (score ≥1: RS, 97%; no-RS, 85%). Fifty-nine of 101 individuals responded to treatment questions. Individuals in both groups reported >30% improvement in pain symptoms with some topical and systemic approaches.

CONCLUSIONS

Individuals with a history of RS developed ocular pain soon after surgery, which persisted for years. Symptom profiles were similar between those with and without RS. Topical and systemic approaches can treat pain in both groups.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Small Incision Lenticule Extraction (SMILE) for Moderate and High Myopia: Seven-Year Outcomes of Refraction, Corneal Tomography, and Wavefront Aberrations

Purpose

To investigate the long-term outcomes of refraction, corneal tomography, and wavefront aberrations after small incision lenticule extraction (SMILE) for moderate and high myopia.

Methods

Prospective, nonconsecutive case series. A total of 26 patients (26 eyes) who underwent SMILE from May 2010 to March 2013 at the Fudan University Eye and ENT Hospital (Shanghai, China) were enrolled. The periods of follow-up were 1 month, 1 year, 5 years, and 7 years after surgery. The routine eye examinations included uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography.

Results

All surgeries were executed without any complications. At the final visit, an UDVA of 20/20 or better was achieved in 26 eyes (100%) and 11 eyes (42%) exhibited no change in CDVA. 9 eyes (35%) gained one line, 6 eyes (23%) gained two lines, and no eyes lost CDVA. 24 eyes (92%) and 26 eyes (100%) were within ±0.5 D and ±1.00 D of the target refraction, respectively. A mean refractive regression of −0.17 D was observed between 1 month and 7 years postoperatively. Mean corneal front curvature (MCFC) was significantly decreased between pre- and post-SMILE surgery (P < 0.0001). Higher-order aberrations (HOAs) and vertical coma were significantly increased after SMILE compared to those measured before surgery (all P < 0.001). There were no significant differences in trefoil and spherical aberration between pre- and post-SMILE surgery (all P > 0.05).

Conclusion

SMILE is an effective, safe, and stable procedure for moderate and high myopia, with relatively constant corneal stability and wavefront aberrations. This trial is registered with ChiCTR-ONRC-13003114.

10-Year Results of FLEx Refractive Surgery

PURPOSE

To evaluate the 10-year results of femtosecond lenticule extraction (FLEx) for treatment of myopia and myopic astigmatism.

METHODS

This long-term follow-up of a prospective clinical trial was conducted at HELIOS Klinikum Erfurt and Phillips University of Marburg, Germany. In 2006, 108 eyes underwent the FLEx procedure. All patients were invited for reexamination 10 years after FLEx treatment for myopia and astigmatism. Visual acuity, objective and manifest refraction, intraocular pressure, and slit-lamp examination and side effects were documented. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuity, objective and manifest refraction, and slit-lamp examination and side effects.

RESULTS

A total of 77 eyes of 40 patients of the original treatment group volunteered for a reexamination 10 years after surgery. The mean age of the patients was 45.9 years; 26 were women and 14 were men. UDVA was 0.09 ± 0.19 logMAR and CDVA was stable at -0.1 ± 0.09 logMAR. More than half of the eyes gained one or two Snellen lines, and none of the eyes lost two or more lines. Over the 10-year period, regression was 0.18 D.

CONCLUSIONS

FLEx has stable results 10 years after treatment for myopia and astigmatism. [J Refract Surg. 2019;35(11):707-711.].

Five-year results of small incision lenticule extraction (SMILE) and femtosecond laser LASIK (FS-LASIK) for myopia

PURPOSE

To compare visual outcomes and aberration outcomes in small incision lenticule extraction (SMILE) versus femtosecond laser LASIK (FS-LASIK).

METHODS

This prospective, comparative, nonrandomized clinical study included 68 eyes of 37 patients receiving SMILE and 55 eyes of 30 patients receiving FS-LASIK between December 2011 and January 2013 at the Fudan University Eye and ENT Hospital (Shanghai, People's Republic of China). Patients were followed up at 3, 6 months and 5 years after surgery. Main outcome measurements included uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, central corneal thickness (CCT), total corneal refractive power (TCRP) and wavefront aberrations.

RESULTS

About 98% (49/50) of treated eyes in the SMILE group and 95% (39/41) in the FS-LASIK group had a postoperative logMAR UDVA of 0 or better. Spherical equivalent (SE) after 5 years was -0.01 ± 0.35 D in the SMILE group and -0.23 ± 0.41 D in the FS-LASIK group. A regression of -0.02 ± 0.39 D in the SMILE group and -0.12 ± 0.32 D in the FS-LASIK group was observed between 6 months and 5 years postoperative time-points. TCRP increased by 0.39 ± 0.38 D in the SMILE group and 0.45 ± 0.49 D in the FS-LASIK group between 6-month and 5-year time-points. However, no statistically significant difference was found between the SMILE and FS-LASIK groups in terms of ∆SE, ∆CCT and ∆TCRP between 6 months and 5 years postoperative time-points.

CONCLUSION

Myopic regression was observed in terms of TCRP but not in subjective refraction. No statistically significant difference in stability was found between SMILE and FS-LASIK.

Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism

AIM

To compare and calculate the 3-year refractive results, higher-order aberrations (HOAs), contrast sensitivity (CS) and dry eye parameters after small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for correction of high myopia and myopic astigmatism.

METHODS

In this prospective, non-randomized comparative study, 78 eyes with spherical equivalent (SE) of -8.11±1.09 diopters (D) received a SMILE surgery, and 65 eyes with SE of -8.05±1.12 D received a wavefront-guided FS-LASIK surgery with the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) for flap cutting. Visual acuity, manifest refraction, CS, HOAs, ocular surface disease index (OSDI) and tear break-up time (TBUT) were evaluated during a 3-year follow-up.

RESULTS

The difference of uncorrected distance visual acuity (UDVA) postoperatively was achieved at 1mo and at 3mo, whereas the difference of the mean UDVA between two groups at 3y were not statistically significant (t=-1.59, P=0.13). The postoperative change of SE was 0.89 D in the FS-LASIK group (t=5.76, P=0.00), and 0.14 D in the SMILE group (t=0.54, P=0.59) from 1mo to 3y after surgery. At 3-year postoperatively, both HOAs and spherical aberrations in the SMILE group were obviously less than those in the FS-LASIK group (P=0.00), but the coma root mean square (RMS) was higher in the SMILE group (0.59±0.26) than in the FS-LASIK group (0.29±0.14, P=0.00). The mesopic CS values between two groups were not statistically significant at 3y postoperatively. Compared with the FS-LASIK group, lower OSDI scores and longer TBUT values were found in the SMILE group at 1mo and 3mo postoperatively. With regard to safety, no eye lost any line of CDVA in both groups at 3y after surgery.

CONCLUSION

Both SMILE and wavefront-guided FS-LASIK procedures provide good visual outcomes. Both procedures are effective and safe, but SMILE surgery achieve more stable long-term refractive outcome and better control of early postoperative dry eye as compared to FS-LASIK.

Twelve-Year Follow-Up of Laser In Situ Keratomileusis for Moderate to High Myopia

Purpose

To assess the long-term clinical outcomes of conventional laser in situ keratomileusis (LASIK) for moderate to high myopia.

Methods

We retrospectively examined sixty-eight eyes of 37 consecutive patients who underwent conventional LASIK for the correction of myopia (−3.00 to −12.75 diopters (D)). At 3 months and 1, 4, 8, and 12 years postoperatively, we assessed the safety, efficacy, predictability, stability, mean keratometry, central corneal thickness, and adverse events.

Results

The safety and efficacy indices were 0.82 ± 0.29 and 0.67 ± 0.37, respectively, 12 years postoperatively. At 12 years, 53% and 75% of the eyes were within 0.5 and 1.0 D, respectively, of the targeted correction. Manifest refraction changes of −0.74 ± 0.99 D occurred from 3 months to 12 years after LASIK (p < 0.001). We found a significant correlation of refractive regression with the changes in keratometric readings from 3 months to 12 years postoperatively (Pearson correlation coefficient, r = −0.28, p = 0.02), but not with the changes in central corneal thickness (r = −0.08, p = 0.63). No vision-threatening complications occurred in any case.

Conclusions

Conventional LASIK offered good safety outcomes during the 12-year observation period. However, the efficacy and the predictability gradually decreased with time owing to myopic regression in relation to corneal steepening.

Four-year observation of predictability and stability of small incision lenticule extraction

BACKGROUND

To investigate long-term refractive outcomes, wavefront aberrations and quality of life after small incision lenticule extraction (SMILE) for moderate to high myopia.

METHODS

A total of 26 patients (47 eyes) with preoperative mean spherical equivalent (SE) of -6.30 ± 1.47 diopters (D) who underwent SMILE were recruited. The measurements included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, wavefront aberrations, and quality of life.

RESULTS

At 4 years postoperatively, UDVA was better than or equal to 20/20 in 92 % of eyes. The efficacy index was 1.07 ± 0.16. 89 % of eyes were within ± 0.5 D of the intended refractive target. No eye lost any Snellen lines. The safety index was 1.16 ± 0.14. No significant changes of SE occurred among postoperative follow-ups at months 1, 3, 6 and years 1, 2, 4 (P > 0.05, Scheffe test). Higher-order aberrations, coma, spherical aberration and higher-order astigmatism increased postoperatively, and no significant changes of aberrations were detected among the 1-month, 6-month or 4-year follow-ups postoperatively (37 eyes). Compared to the spectacles group, the surgery group showed a significantly higher total score on quality of life (45.71 ± 2.61 vs 39.96 ± 3.56, P < 0.001).

CONCLUSIONS

SMILE provides a predictable and stable correction of moderate to high myopia as documented by long-term follow-up.

Effect of orthokeratology in patients with myopic regression after refractive surgery

PURPOSE

To evaluate the clinical effect of orthokeratology (ortho-K) lenses and to introduce the fitting steps of ortho-K lens for myopic regression after keratorefractive surgery.

METHODS

Twenty-one eyes from 12 patients with myopic regression after keratorefractive surgery were fitted with ortho-K lenses and followed up for 12.11±3.68 months. The mean K value of the peripheral cornea was used to speculate preoperative central corneal K value, estimated K. After dispensing the lenses according to estimated K, biomicroscopic examination including fluorescein staining and over-refraction were performed to determine the final K and final lens power.

RESULTS

LogMAR uncorrected visual acuity was 0.48±0.39 before and 0.00±0.00 after wearing ortho-K lenses (p<0.001). Pre-fitted refractive error was -1.87±1.05 diopters (D) in myopia, 0.54±0.42 D in astigmatism, and spherical equivalent of -2.14±1.01 D. At the final visit myopia level and spherical equivalent significantly decreased to -0.73±0.84 D (p<0.001) and -1.01±0.87 D (p<0.001), respectively. Estimated K was 8.07±0.36 mm, and final K used for ortho-K prescription was 8.19±0.30 mm. Final K significantly correlated with K value of pre-fitted peripheral cornea (r=0.737, p<0.001) and estimated K (r=0.721, p<0.001), respectively. There was no correlation between pre-fitted degree of myopia and the Final lens power (r=0.429, p=0.053).

CONCLUSIONS

Ortho-K lenses may be an effective solution for patients with myopic regression following keratorefractive surgery. Estimated K value can be used as reference value in ortho-K prescription.

Chronic dry eye symptoms after LASIK: parallels and lessons to be learned from other persistent post-operative pain disorders

Laser in-situ keratomileusis (LASIK) is a commonly performed surgical procedure used to correct refractive error. LASIK surgery involves cutting a corneal flap and ablating the stroma underneath, with known damage to corneal nerves. Despite this, the epidemiology of persistent pain and other long-term outcomes after LASIK surgery are not well understood. Available data suggest that approximately 20-55% of patients report persistent eye symptoms (generally regarded as at least 6 months post-operation) after LASIK surgery. While it was initially believed that these symptoms were caused by ocular surface dryness, and referred to as “dry eye,” it is now increasingly understood that corneal nerve damage produced by LASIK surgery resembles the pathologic neuroplasticity associated with other forms of persistent post-operative pain. In susceptible patients, these neuropathological changes, including peripheral sensitization, central sensitization, and altered descending modulation, may underlie certain persistent dry eye symptoms after LASIK surgery. This review will focus on the known epidemiology of symptoms after LASIK and discuss mechanisms of persistent post-op pain due to nerve injury that may be relevant to these patients. Potential preventative and treatment options based on approaches used for other forms of persistent post-op pain and their application to LASIK patients are also discussed. Finally, the concept of genetic susceptibility to post-LASIK ocular surface pain is presented.

Eight-year follow-up of posterior chamber phakic intraocular lens implantation for moderate to high myopia

PURPOSE

To assess the long-term clinical outcomes of Implantable Collamer Lens (Visian ICL; STAAR Surgical) implantation for moderate to high myopia.

DESIGN

Retrospective observational case series.

METHODS

This study evaluated 41 eyes of 41 patients with myopic refractive errors of -4.00 to -15.25 diopters (D) who underwent ICL implantation and routine postoperative examinations. Before surgery, and 1 and 6 months and 1, 4 and 8 years after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery.

RESULTS

The safety and efficacy indices were 1.13 ± 0.27 and 0.83 ± 0.36. At 8 years, 68.3% and 85.4% of the eyes were within 0.5 and 1.0 D, respectively, of the targeted correction. Manifest refraction changes of -0.32 ± 0.73 D occurred between 1 month and 8 years. The mean endothelial cell loss from preoperative levels was 6.2% at 8 years. Two eyes (4.9%) developed clinically significant symptomatic cataract during the follow-up period. Simultaneous lens extraction and phacoemulsification with IOL implantation was successfully performed in these 2 eyes.

CONCLUSIONS

According to our experience, ICL implantation was overall good in measures of safety, efficacy, predictability, and stability for the correction of moderate to high myopia during the 8-year observation period, suggesting its long-term viability as a surgical option for the treatment of such eyes.

Change in keratometry after myopic laser in situ keratomileusis and photorefractive keratectomy

PURPOSE

To compare the change in keratometry (K), spherical equivalent (SE), and visual acuity after myopic laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

SETTING

Academic tertiary care center.

DESIGN

Retrospective review.

METHODS

The postoperative K, SE, and uncorrected and corrected distance visual acuities were measured 6 months, 9 months, 1 year, 2 years, 3 years, 4 to 5 years, 6 to 7 years, and 8+ years postoperatively. A difference (Δ) for each variable was calculated from its 6-month postoperative baseline. The rates of change were grouped based on the magnitude of myopic correction (0.00 to 2.99 diopters [D]; 3.00 to 5.99 D; 6.00 to 8.99 D), type of surgery (LASIK versus PRK), and age (<34 years; 34 to 45 years; >45 years).

RESULTS

Statistically significant differences were found in the rates of change between low and moderate corrections to high corrections for ΔKavg (P=.0472 and P=.0091, respectively) and ΔSE (both P<.0001). Statistically significant differences were found in the rate of change in ΔKavg between all 3 ages groups (P=.0330, P=.0051, and P<.0001) and in ΔSE between ages less than 34 years and 34 to 45 years to ages over 45 years (P=.0158 and P=.0015, respectively). There was no significant difference in the rate of change in ΔKavg and ΔSE between LASIK and PRK (P=.3599 and P=.9403, respectively).

CONCLUSION

There was keratometric and refractive regression for myopic LASIK, with the rate of regression depending on treatment magnitude and age.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

[Influence of corneal biomechanical properties on myopic regression after laser in situ keratomileusis]

BACKGROUND

Laser in situ keratomileusis is a safe and accepted method for correcting myopia. The operational results in terms of accuracy as well as the subjective acceptance of patients for corrections to - 8 D are now considered to be promising (Seiler, Refraktive Chirurgie der Hornhaut, 2000); however, postoperative results show individual patient problems in long-term stability. It is believed that the preoperative condition of the cornea (e.g. thickness, biomechanical properties) could have an influence on postoperative problems such as myopic regression.

METHOD

This study included a total of 46 eyes from 25 patients. At 3 months postoperatively, 15 patients (19 eyes) showed a SEQ of -0.50 D or more. Within this group, 11 patients (15 eyes) developed a regression (regression group) within the first 3 postoperative months. The remainder of the total group did not show any regression (stability group). The subjects of this study were on average 33 ± 8 years (stability group) and 31 ± 7 years old (regression group). The corneal thickness was tested and refractive error, visual acuity (BCVA/UCVA) and intraocular pressure was measured. In addition, the corneal hysteresis (CH) and corneal resistance factor (CRF) were determined.

RESULTS

The mean preoperative spherical equivalent refraction was -3.14 D ± 1.41 D (SE) in the stability group and - 6.47 D ± 1.40 D (p = 0.001)in the regression group. Also, the postoperative spherical equivalents were statistically significant different (p < 0.05). In contrast, the mean preoperative corneal thickness showed no differences in both groups (p = 0.96) (stability group 563 ± 36 µm and regression group 563 ± 28 µm).

CONCLUSIONS

The aim of the study to detect a possible causal relationship between myopia regression after LASIK and the biomechanical properties of the cornea and corneal thickness could not be clearly identified.

Effect of timolol on refractive outcomes in eyes with myopic regression after laser in situ keratomileusis: a prospective randomized clinical trial

PURPOSE

To compare the effects of timolol on refractive outcomes in eyes with myopic regression after laser in situ keratomileusis (LASIK) with a control-matched group.

DESIGN

Prospective, randomized, parallel-controlled, double-masked clinical trial. A computer-generated randomization list based on random block permutation (length 4 to 8) was used for treatment allocation.

METHODS

setting: Basir Eye Center, Tehran, Iran.

PATIENT POPULATION

Of 124 eyes with myopic regression after LASIK using Technolas 217-Z, 45 eyes in each group were analyzed.

INTERVENTION

Patients were randomly assigned into either Group 1, who received timolol 0.5% eye drops, or Group 2, who received artificial tears for 6 months.

MAIN OUTCOME MEASURE

Spherical equivalent (SE) at 6 months posttreatment.

RESULTS

In Group 1, SE improved from -1.48 ± 0.99 diopter (D) before treatment to -0.88 ± 0.91 D and -0.86 ± 0.93 D 6 months after treatment and 6 months after timolol discontinuation, respectively (P < .001). In Group 2, it was -1.57 ± 0.67 D, -1.83 ± 0.76 D, and -1.91 ± 0.70 D, respectively (P < .001). SE was significantly better in Group 1 6 months after treatment and 6 months after discontinuation of treatment (P < .001 for both comparisons). There was a 0.26 D decrease in SE improvement every 4 months after the surgery in the Group 1 (P < .001).

CONCLUSIONS

Timolol application is effective for the treatment of myopic regression after LASIK compared with control group. Its effects last for at least 6 months after its discontinuation.

Time course of refractive and corneal astigmatism after laser in situ keratomileusis for moderate to high astigmatism

PURPOSE

To assess the time course of refractive and corneal astigmatism after laser in situ keratomileusis (LASIK) in eyes with moderate to high astigmatism.

SETTING

Department of Ophthalmology, Kitasato University, Kanagawa, Japan.

DESIGN

Retrospective case series.

METHODS

Keratometric readings and corneal astigmatism were determined with an autokeratometer in consecutive patients who had LASIK for moderate to high astigmatism (≥2.00 diopters [D]).

RESULTS

The study enrolled 48 eyes of 35 patients with a mean age of 34.0 years ± 8.1 (SD), a mean spherical error of -5.10 ± 2.11 D, and a mean cylindrical error of -2.74 ± 0.99 D. Postoperatively, the mean spherical refraction changed significantly from 0.38 ± 0.80 D at 1 week to -0.13 ± 0.90 D at 1 year (P<.001, Wilcoxon signed-rank test). The mean cylindrical refraction showed no significant change (-0.67 ± 0.54 D at 1 week to -0.63 ± 0.63 D at 1 year) (P=.54). There were significant increases in the flattest and steepest keratometry readings at 1 week and at 1 year. However, no significant change in corneal astigmatism was found at either time point (P=.10).

CONCLUSIONS

After LASIK, there was significant refractive regression in the spherical component but not in the cylindrical component. This suggests that refractive regression occurs by corneal steepening in the spherical component and that astigmatic regression does not occur, even in moderately to highly astigmatic eyes.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Analysis of the reasons for not undergoing laser corneal refractive surgery in 611 patients

To determine and analyze the reasons for patients not undergoing laser corneal refractive surgery. A retrospective observational study was conducted to analyze the reasons for not undergoing laser corneal refractive surgery in 611 patients. In this study, 611 (14.34%) among 4,262 enrolled patients did not undergo laser corneal refractive surgery. Among these 611 patients, the common reasons for not undergoing laser corneal refractive surgery were concern about the surgery (366 patients, 59.90%), insufficient corneal thickness (72 patients, 11.78%), too high corneal refractive power (36 patients, 5.89%), dry eye (33 patients, 5.40%), high intraocular pressure (22 patients, 3.60%), poor corrected visual acuity (25 patients, 4.09%), retinal diseases (23 patients, 3.76%) and others (34 patients, 5.56%). The concern about surgery is the primary factor for the patients not undergoing laser corneal refractive surgery.

Long-term follow-up of photorefractive keratectomy for myopia: Comparative study of excimer lasers

PURPOSE

To compare the long-term results of photorefractive keratectomy (PRK) for low to moderate myopia performed using a broad-beam laser system or a scanning-slit laser system.

SETTING

Department of Ophthalmology, University of Helsinki, Helsinki, Finland.

DESIGN

Case-control study.

METHODS

This follow-up study comprised eyes with myopia (-1.25 to -7.00 diopters [D]) or myopic astigmatism (astigmatism lower than -2.50 D) corrected by PRK using a broad-beam (Visx) or scanning-slit (Nidek) laser. Follow-up included a visit at 3 months and at more than 8 years. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction were recorded.

RESULTS

The broad-beam group comprised 27 eyes and the scanning-slit group, 34 eyes. At the last postoperative follow-up, the UDVA was 0.0 or better in 55% of eyes in the broad-beam group and 65% of eyes in the scanning-slit group. The CDVA was 0.0 or better in all eyes in the broad-beam group and 96% of eyes in the scanning-slit group. Regarding predictability, 48% and 73% of the eyes, respectively, were within ±0.50 D of the intended spherical equivalent refraction. There were no statistically significant differences between the 2 laser groups in any preoperative or postoperative parameter.

CONCLUSION

There were no significant differences in UDVA, CDVA, or SE after PRK for low to moderate myopia between the broad-beam laser system and the scanning-slit laser system.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Reasons for not performing LASIK in refractive surgery candidates in Yemen

PURPOSE

To determine and analyze the reasons that laser in situ keratomileusis (LASIK) was not performed in patients who requested refractive surgical correction of their refractive errors.

METHODS

A retrospective observational study was performed in Yemen Magrabi Hospital between June 2005 and October 2006; the case records of 1596 new consecutive patients who presented for refractive surgery at our refractive surgery unit were reviewed. Data on the ocular status, refractive problems, and investigations performed were analyzed. The reasons for not performing LASIK in the cases that were rejected were recorded and analyzed.

RESULTS

A total of 1191 patients (74.6%) were advised to have LASIK of the 1596 patients examined. LASIK was not advised in 405 patients (25.4%). The most common reasons for rejecting LASIK were suboptimal central corneal thickness (25.9%), high myopia >-11.00 D (17.0%), keratoconus (15.5%), cataract (11.4%), and suspicious corneal topography (forme fruste keratoconus) (9.4%).

CONCLUSIONS

Patients who request refractive surgery have a variety of problems and attention must be given to these patients. Suboptimal corneal thickness, high amount of refractive error, and keratoconus were found to be the leading causes of not performing LASIK in Yemeni patients.